Cell surface glycoproteins would be isolated from embryonic mouse cerebellum at different developmental stages and characterized by affinity binding to plant lectins immobilized on Sepharose. These studies should determine the fraction of cell surface glycoproteins under developmental regulation. The importance of both cell surface carbohydrates and carbohydrate-binding proteins (lectins) to cell migrations and interactions would be assessed in vitro with monosaccharides and lectins immobilized on the surface of microwell tissue culture dishes. Detailed analysis of cell migration on derivatized substrata would be made with a time-lapse television system adapted for use with an inverted phase-optics microscope. Cerebellar cell types would be identified by electron microscopy and by specific cell markers. Cell separation following cell agglutination in the presence of plant lectins and sedimentation on a ficoll-isopague gradient would also be assessed by electron microscopy.